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<p>Am 06.05.2013 23:10, schrieb Johannes Zarl:</p>
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<pre>On Monday 06 May 2013 22:35:39 Johannes Zarl wrote:</pre>
<blockquote type="cite" style="padding-left:5px; border-left:#1010ff 2px solid; margin-left:5px; width:100%">I didn't find anything yet in the strace.log, but I'll keep you posted.</blockquote>
<pre>Ah, just as I was done sending the other mail, I noticed something: There are
some file accesses to some path under "/mnt/server/...". Are your files lying
on an nfs share, by any chance?
I imagine that the thumbnail creation (hitting on a lot of files) may not play
along well with a high-latency storage. AFAIK the ImageManager cancels
thumbnail requests for low-priority thumbnails when others are more urgent. If
you add a high-latency storage into the mix and start scrolling/browsing your
images, most thumbnail requests are probably cancelled before they start.
Maybe the long time spent in futexes could also mean that KPA gets preempted a
lot because of NFS being too slow (for KPA's heavy access patterns). Is it
only KPA that becomes slow, or does it tear down the performance of other
desktop programs or the file manager?
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<p>The share is a Windows share (Samba) on a local server and mounted with the cifs file system. It's usally not slow, no issue at all with other programs. After loading KPA there are few background jobs, but they are done quickly. KPA starts becoming slow later even when I wait until the background jobs are done.</p>
<p>For testing I select a path with 25 images (jpegs 1.3 MP, about 300 kB per file). The thumbnails are displayed very fast. But when I double click on a thumbnail it takes a while for the detail window to appear (This time: 34 seconds until the image is visible, sometimes it's a bit faster). PgDn is sometimes fast for a few pictures (e.g. 5 to 6), then there is a longer delay (typically 5 - 10 seconds). Closing the detail window sometimes takes very long, but right now it did close immediately. Clicking on 'Back' takes quite long, opening the 25 image tumbnails again takes longer than initially (about 10 secs).</p>
<p>It looks like there is a lot more network traffic going on than one would expect. All the 25 pictures together are only 7,5 MB.</p>
<p>For comparison I opened the folder on the mounted share directly with the default file manager, doubled clicked on the first image, which opens it with eog and scrolled thru the images with PgDn. This is fast as lightning. No delay at all.</p>
<p>Manfred</p>
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